NPTV6_READY
(cfg->flags & NPTV6_READY) == 0)
cfg->flags |= NPTV6_READY;
cfg->flags &= ~NPTV6_READY;
if ((cfg->flags & NPTV6_READY) == 0)
cfg->flags &= ~NPTV6_READY;
if (cfg->flags & NPTV6_READY)
MPASS(!(cfg->flags & NPTV6_READY));